FIG. 2.

Postinfection treatment with EB blocks viral cell-to-cell spreading. (A) Cell cultures (8 × 10⁴ cells/well) in serum-supplemented DMEM were infected with HSV-1 KOS (700 PFU/well). EB either was added 1 h postinfection and remained present throughout the experiment (● and Δ) or was present from 1 h before until 1 h after infection (○). One day later, the cells were fixed in 10% formaldehyde in PBS and the number of plaques were scored (● and ○; control score, 13 ± 1.7; [n = 6]) and their size was determined (Δ). All data points are means of triplicate measurements with standard errors of the means. (B) The distribution of plaque size in untreated controls (black bars) and in cultures treated postinfection with 25 μM EB (shaded bars) is shown.